<MudChipSet @bind-SelectedValues="_selected" SelectionMode="SelectionMode.MultiSelection">
    <MudChip Value="@("Milk")"/>
    <MudChip Value="@("Eggs")"/>
    <MudChip Value="@("Soap")"/>
    <MudChip Value="@("Corn flakes")"/>
    <MudChip Value="@("Salad")"/>
    <MudChip Value="@("Apples")"/>
    <MudChip Value="@("Red wine")"/>
</MudChipSet>

@if (_selected is { Count: > 0 }) {
    <MudText>@string.Join(", ", _selected.OrderBy(x => x))</MudText>
}
else {
    <MudText>Nothing selected.</MudText>
}
<MudButton id="set-null" OnClick="SetNull">Set Null</MudButton>
<MudButton id="set-empty" OnClick="SetEmpty">Set Empty</MudButton>
@code
{
    private IReadOnlyCollection<string>? _selected;

    private void SetNull() => _selected = null;

    private void SetEmpty() => _selected = Array.Empty<string>();
}